 /***************************************************************************************************
  * Copyright (c) 2006 IBM Corporation and others. All rights reserved. This program and the
  * accompanying materials are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors: IBM Corporation - initial API and implementation
  **************************************************************************************************/
 package org.eclipse.ui.intro.universal;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExecutableExtension;
 import org.eclipse.core.runtime.IExecutableExtensionFactory;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.ui.internal.intro.universal.UniversalIntroPlugin;
 import org.eclipse.ui.internal.intro.universal.WelcomeCustomizationPreferencePage;

 /**
  * Factory for the intro's public extensions.
  * <p>
  * This allows the extensions to be made available for use by RCP applications without exposing
  * their concrete implementation classes.
  * </p>
  * <p>
  * Currently supported plug-in extensions:
  * <ul>
  * <li>welcomeCustomization - a preference page that allows user customization of the shared
  * Welcome.</li>
  * </ul>
  * <p>This class should be referenced in extensions but not subclassed
  * or instantiated programmatically.
  *
  * @since 3.2
  */

 public class ExtensionFactory implements IExecutableExtensionFactory, IExecutableExtension {

     private String id;
     private IConfigurationElement config;
     private String propertyName;
     private static final String WELCOME_CUSTOMIZATION_PREFERENCE_PAGE = "welcomeCustomization"; //$NON-NLS-1$

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.core.runtime.IExecutableExtensionFactory#create()
      */
     public Object create() throws CoreException {
         if (WELCOME_CUSTOMIZATION_PREFERENCE_PAGE.equals(id))
             return configure(new WelcomeCustomizationPreferencePage());

         throw new CoreException(new Status(IStatus.ERROR, UniversalIntroPlugin.PLUGIN_ID, 0,
                 "Unknown id in data argument for " + getClass(), null)); //$NON-NLS-1$
 }

     private Object configure(Object obj) throws CoreException {
         if (obj instanceof IExecutableExtension) {
             ((IExecutableExtension) obj).setInitializationData(config, propertyName, null);
         }
         return obj;
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.core.runtime.IExecutableExtension#setInitializationData(org.eclipse.core.runtime.IConfigurationElement,
      * java.lang.String, java.lang.Object)
      */
     public void setInitializationData(IConfigurationElement config, String propertyName, Object data)
             throws CoreException {
         if (data instanceof String )
             id = (String ) data;
         else
             throw new CoreException(new Status(IStatus.ERROR, UniversalIntroPlugin.PLUGIN_ID, 0,
                     "Data argument must be a String for " + getClass(), null)); //$NON-NLS-1$
 this.config = config;
         this.propertyName = propertyName;
     }
 }
